2006 MINI Bucks...
 

Hello All,
First time on the Mini forum. We have a 2006 Cooper S, that has about 150k on it. Just replaced the plugs, wires, ignition coil, O2 sensor....
So when driving the car, it starts out just fine. can shift through all gears,, accelerates just fine. After about 20 or 30 minutes, regardless of gear, it "bucks"...not sure how to describe this, almost like if I were to keep accelerating the engine might drop out?? Anyway, If I push in clutch, and give it gas, rpms go up, you hear the engine roar, all seems good. I don't think its a fuel flow issue.
What should I be looking at to resolve this?

Thanks for any helpful suggestions.
respectfully,

Hello and welcome to the forum! Have you tried pulling any of the fault codes? This may help you in determining where the issue is coming from.

Interestingly enough, there are no codes....

Have you ever change the in tank fuel filter? Also check the two vacuum lines under the intercooler on the passenger side. One runs to the fuel pressure regulator and the other T’s into the vent solenoid for the fuel tank. The boots are prone to dry rot and creating a boost leak.

While you have the filter housing out see how the fuel looks. My 2005 had some water in the tank when I bought it and would did when it got to 1/4 tank. The filter was charcoal black when I changed it a few weeks ago. I suspect it was the original filter from 2005!